Method of batch processing discrete articles



Aug. 18, 1953 G. M. FLYNN METHOD OF BATCH PROCESSING DISCRETE ARTICLESFiled Dec. 2'7, 1951 Zez/eb Z Z j 1 2 5 n LL" T fl 5?; E A4\ u nrrr itlJ9 INVENTOR.

Geog-9815f. F9222, BY

i atentecl Aug. 18, 195 3 UNITED STATES PATENT OFFICE METHOD OF BATCHPROCESSING DISCRETE ARTICLES 2 Claims. 1

This invention relates to the processing of various products or articlesand, in certain of its aspects, is particularly suited to the processingof canned products, though in its broader aspects it may be used toadvantage in processing various other products and discrete articles inindustrial operations.

In the method of my invention, the articles or products are treated in abody of liquid within a suitable receptacle and, after treatment, aredischarged from the receptacle through a continuous column of liquidextending from the interior of the receptacle to the exterior thereof.That expedites handling of the treated articles, an importantconsideration in many industrial operations, and also guards thearticles against injury when they are of a character to be bruised orotherwise injured by contact one with the other if discharged from thereceptacle downward through the air. articles through a continuouscolumn of liquid, as above stated, is of the essence of the method of myinvention and, so far as I am aware, is fundamentally new.

In the processing of canned foods it is the usual practice to exhaust asmuch air as practicable from the cans by thermal or mechanical means,before they are closed and hermetically sealed. The filled and closedcans, after they leave the closing machine, are manually placed inreceptacles known as retort baskets or crates. The baskets aremechanically hoisted and lowered into vertical retorts. After a retorthas been loaded with baskets of cans, the cover of the retort is closedand sealed and steam under suitable pressure is admitted to the retortfor an appropriate time for effecting sterilization of the filled andclosed cans. Upon completion of the sterilizing operation it isnecessary in many instances to partially cool the cans in water, toreduce the pressure therein to a sufliciently low value, before theretort can be opened to the atmosphere preparatory to removing the canstherefrom. Such pressure cooling is usually necessary for cans of sizestwo and one half or larger, but is not usually necessary for cans of thesmaller sizes. In either case. the baskets of cans are mechanicallywithdrawn from the retorts and passed through an elongated tank orcooling canal containing cooling water in which the baskets areimmersed. After cooling sufficiently the cans are removed from thebaskets individually by hand. Handling of the cans .in the manner above.described necessitates con- The discharge of the siderable manual laborand the use of a large number of baskets. Those baskets occupyconsiderable floor space which would otherwise be available forprocessing equipment. That is objectionable for obvious reasons. Thepotential productive capacity of the retorts is reduced by the spaceoccupied by the individual baskets and allowed between the severalbaskets included in each retort load or batch. Under the presentpractice, in handling the sealed cans, both before and aftersterilization, there is risk that the cans may be dropped, or forcefullystruck one against the other, with the result that a slight opening maybe sprung in the cans. When the cans are passed through the water of thecooling canal, the resultant cooling of the contents of the cans causesa partial vacuum therein, and if any of the cans have slight openingssprung in them unsterile cooling water will be drawn through thoseopenings into the cans, contaminating the contents thereof. Also, andfor analogous reasons, there is risk that unsterile water adhering tothe cans will be drawn into the cans after they pass out of the coolingcanal. In either case spoilage of the contents of such cans will result.It is known, as a labor saving operation in the processing of small andexceptionally sturdy cans, such as flat sardine cans, to deliverautomatically the individual filled and closed cans into a body of waterwithin a vertical retort, after which the water is discharged from theretort, the cans are steam sterilized, and the bottom of the retort isopened and the cans are discharged through the atmosphere onto a,suitable conveyor or the like. This latter procedure is not used withcans of larger sizes and less resistant structure, since the amount ofspoilage attending this abusive can discharging operation would renderit prohibitive.

I shall first describe the method of my invention, by way of exampleonly, as used for processing canned food products. In the method of myinvention, as used for the processing of canned products, the objectionsto the presently known methods, above briefly referred to, are avoided.The individual filled and closed cans are delivered automatically fromthe closing machine into a retort containing a column of water ofconsiderable depth which serves to cushion the cans and prevent injurythereto, after which the cans are steam sterilized in the retort and,upon completion of the sterilizing operation, are discharged from theretort to a point exterior thereof 7 and downward through a continuousretort are steam sterilized, the steam is shut Lair 7 and cooling wateris admitted to .the retortproviding therein a water column ofappropriate depth effective for cooling the cans and,'upon completion ofthe cooling operation, the :bottom of the retort is opened and the cansare .discharged therefrom while the water column within the retort ismaintained, the cans moving downward through a body of water which iscontinuous and extends to a point exterior of the retort, this body ofwater comprising the water column maintained within the retort. Afterdischarge of the cans from the retort, the bottom of the retort is againclosed, with the water column remaining therein, it being noted that thewater of this column has been heated to a substantial extent by heatabstracted from the cans cooled thereby, and a further charge of filledand closed cans is delivered to the retort, such cans being heated tosome extent by the water then in the retort. Further objects andadvantages of my invention will appear from the detail description.

The single figure of the drawing is a View partly in section and partlyin elevation, somewhat diagrammatic, of one means for practicing themethod of my invention.

This application is a continuation-in-part of my copending applicationfor Method of Batch ?rocessing Articles, Serial No. 36,682, filed July2, 1948, now abandoned.

The means or apparatus shownin the drawing comprises a receptacle orretort I having a cylindrical body 2 provided with upper and lowerfrusto-conical heads 3 and 4, respectively. The upper head 3 is providedwith an upwardly extending cylindrical inlet neck '5 controlled 'by agate valve 6, of suitable known type, interposed therein. A track i, ofknown type, which may lead from a can closing machine, extends at adownward inclination to the upper end of'neck 5 for delivering theretofilled and-closed cans c. A steam supply pipe 8, leading from a suitablesource of supply of steam under pressure, opens into neck 5 adjacent andbelow the gate valve'6. Pipe 8 is provided with a control valve -9,shown as a manually operated valve of known type. A suitable pressuregauge I is mounted on steam supply pipe 8, in communication with theinterior of the retort.

A cylindrical discharge neck II extends downward from head 4 and isprovided with a gate valve I2 of suitable known type interposed therein.A pipe I3 opens into the neck I I, above valve I2, and is provided, atits outerend, with a T i l to which are connected two pipes I5 and H5provided with manually operated control valves i1 and I8, respectively,of known type. Pipe may be connected to a suitable source of supply ofcooling water and pipe l6 may bea drain pipe connected to a suitable.point of discharge. The discharge neck II extends downward a materialdistance into a tank I9 of elongated rectangular or oblong shape inplanzfor containing .cooling water, commonly termed a cooling canal. Thetank I9 extends a considerable distance to one side of neck II andreceives, at its side remote from neck II, the upper run 20a of anendless belt conveyor 20 of known type, which enters the tank I9 at oneend thereof and passes upward out of the tank at the other end thereof.A deflector 2| is secured to the other side of tank I9, in underlyingrelation t'o neck I I, and extends at an inclination downward to theupper run 26a of conveyor 26, for directing onto upper run 20a cansdischarged through neck I I.

A pipe 22 connects tank I9, at a oint a substantial'distance belowdischarge neck II, to the intake of a pump 23 of suitable known type.The

discharge of pump 23 is connected by a pipe 24 to pipeB, between valve 9thereof and the inlet neck"5 of thereceptacle or retort I. The pipe.24.:is" provided with a manually operated control valve 25, of suitableknown type, similar to the .valves 9, I1 and I8. In the use of theapparatus for the handling or treatment of articles or products whichare heavier than the treating liquid, the valve 25'is closed and thepump 23 is not operated, as will be explained more fully later.

The apparatus shown in the drawing is by way of example onlyand may bevaried considerably in detail without departing from my invention. Inpracticing the method of my invention,

with the apparatus illustrated, with the lower gate valve I2 closed andvalve9 closed and the upper gate valve 6 open, valve I! is opened andwater under appropriate pressure is admitted to the retort I so as toprovide therein a water column of appropriate height. It may be assumed,for example, that the water level, before delivery of cans to theretort, is that indicated in the drawing, the water is controlled to adesired temperature, and the water volume is such that,

"when thepro'per number of cans have been delivered to the retort, thewater level will be at the top of the retort, as indicated. The filledand closed cans c are then delivered from track I downward into retortI, in suitable number, after which the upper gate valve 6 is closed, thelower gate valve I2 remaining closed, and the valves I? and I8 beingclosed, it being understood that 'valve I1 is closed when the properamount of water has been supplied to the retort. After closing-gatevalve 6, the drain valve I8 is opened and the control valve 9 in thesteam pipe 8 is opened, admitting steam under proper pressure to theinterior of the retort. The water is then "discharged from the retortthrough pipes I3 and I6, by gravity and by the steam pressure exerted onthe water column. After the water has been discharged from the retort,valve I8 is closed and the filled and closed cans within the retort aresteam processed at appropriate pressure and for an appropriate length oftime to effect sterlizing thereof. When the cans are delivered to theretort, they drop into the water column therein and sink gently andslowly through the water,

which effectively-guards the cans against injury. During the sterilizingoperation, the cans remain quiescent within the retort, so that there isno risk of injury to the cansat that time. It will be to the retort andsterilizing them, they are ef- Upon completion of the sterilizingoperation,

"valve I! is opened and cooling water, under appropriate pressure, issupplied to the retort I so as to provide therein a water column inwhich the cans are immersed. The entering cooling water condenses thesteam within the retort and/or volumetrically displaces the steamthrough valve 9, which is closed when the retort is properly filled withwater. As will be explained more fully presently, a controlled partialvacuum is formed within the retort when the cans are dischargedtherefrom. This controlled negative pressure within the retort above thewater column may be indicated by the gauge It and is controllable suchthat the atmospheric pressure effective upon the water in thecoolingcanal will support the water column at the de sired height within theretort I, when the lower or discharge gate valve I2 is open. After thecans have been properly cooled, the gate valve I2 is opened and thecooled cans pass downward through neck ll into the tank or cooling canall9 and are deflected, by the deflector 21, onto the upper run 200. ofthe conveyor 20, which removes the cans from the cooling canal andconveys them to a suitable point, such as a labeling machine. Duringdischarge of the cans from the retort, they pass downward through acontinuous body of water comprising the water column within the retortand the body of water exterior to the retort, within the tank or canalHi, this latter body of water being in free communication with andconstituting an extension of the water column within the retort. Thecans being discharged from the retort sink gently and slowly through thewater and are thus effectively guarded against injury,

After all of the cans have been dischrged from the retort, the lowergate valve I2 is closed so as to retain the water column within theretort. The Water of that column has absorbed considerable heat from thecans cooled thereby. The upper gate valve 6 is then opened and asucceeding batch of filled and closed cansis delivered to the retortdownward into the water column therein. Since the water has been heatedto a controlled degree by the cans of the preceding batch, it does notexert any objectionable chilling effect upon the entering cans.

Referring further to the controlled negative pressure which is essentialto the maintaining of the designated water column in the retort duringdischarge of the cans, it may be assumed, by way of example, that thecans are cooled until the water within the retort is at a temperature of200 F., that the water level of the filled retort is 11.5 feet above thesurface of the water in the cooling canal, and the water in the coolingcanal i9 is at a temperature of 70 F., when the gate valve I2 is opened.The vapor pressure above the water at 200 F., within the retort is 11.5pounds per square inch, and assuming the prevailing atmospheric pressureon the water in the canal l9 to be 14.7 pounds per square inch, thepressure differential is 3.2 pounds per square inch, which will supporta 7.5 foot column of water. Therefore as the cans are discharged fromthe retort, the level of the water column within the retort will fall tothe desired height of 7.5 feet above the level of the water in thecooling canal l9. As the cans sink in the cooling canal [9, because theyare heavier than the water within the system, so also is the lighter 200F. water within retort l retained substantially separate from theheavier 70 F., water within cooling canal l9. When all of the cans havebeen discharged from the retort, the gate valve I2 may be closed and thecycle repeated.

It will be seen, from the above, that by the ing tanks or receptacles.

" method of my invention I have eliminated considerable manual handlingof the cans and the use of a large number of retort crates or basketsand the basket transferring mechanism, required under the presentpractice above mentioned. I have thereby reduced the manpowerrequirements, effected a substantial saving in required manufacturingfloor space and, by increasing the productive capacity of the retortsthrough the elimination of retort baskets and the reduction in essentialretort cooling time peculiar to my method, have materially increased theretort output, while providing a comparatively simple processingapparatus which is highly flexible, in respect to the range of can sizeswhich can be processed therein, compared to the known and presently usedautomatic can retorting systems.

In the above description of my invention I have referred to the use ofwater and steam as the heat transfer media, because those are the onescommonly used in the food canning and analogous industries. It Will beunderstood, however, that my invention comprehends the use of anysuitable fluid heat transfer medium and that the appropriate negativepressure within the receptacle or retort, for maintaining the desiredliquid column therein, may be established in any suitable manner. Whilethe method of my invention is particularly suitable, in certain of itsaspects, for the processing'of canned foods and the like, it is notlimited to that use and, in the broader aspects of my invention,'may beused for processing any products adaptable to treatment in the mannerabove described. The apparatus is shown semi-diagrammatically and issubject to variations such as may be required in practice.

It is well known to' subject many food products to preparatory treatmentunder liquids preliminary to canning, preserving or other processing.Apples are usually blanched before canning by being placed in brine orwater and subjected to a high vacuum, or by heating in water for severalhours at F. Potatoes, after peeling, are immersed in an 0.5% sodiumbisulfite solution to prevent browning. Hominy is treated with boilinglye solution, followed by bleaching, and leaching with water. Dry beansmay be soaked in water for as long as sixteen hours to obtain optimumquality, before blanching and canning. Fish, after dressing, areimmersed in strong brine for as long as two hours to extract moisturefrom the tissue. In walnut shelling operations, small pieces of nutmeats are-separated and recovered from intermingled shell fragments byimmersing the mixture in water under vacuum to effect an increase in theapparent specific gravity of the shell fragments, sufficient to obtainsubsequent flotation separation of the meats from the shells.

The common practice, in accumulating or treating fruits and vegetablesand analogous products in batches under liquids, preparatory to canningor other processing thereof, is to place the articles or products inbaskets for transfer into and subsequent removal from suitable treat-That is time consuming and necessitates equipment for handling thebaskets. An alternative common practice is to place the articlesdirectly into the treating receptacle, which subsequently entails eithermanual or mechanical upward removal of the articles, or their downwarddischarge from the receptacle through the atmosphere. The depth in thereceptacle of articles which can be discharged downward through theatmosphere is z igeiaeso dimited by pr 'actical consideratidns, asisf'also the deptn of a receptacle; which can zbeiunloaded "manuallyj'the complexity of upward mechanical removal 'of the treated articles"being obvious,

fi llla'rly from batteries or '-'receptacle's "of maximum depth andmiriimum' floorzspac pared "with downward discharge of the treatedarticlesfrom the receptacle.

In the method of my Y invention, i'tll'e fruits, vegetables or otherproducts, are delivered directly into the :"liq'uid filled treating orFholding receptacle without I the use of baskets or other conta'iners.Atft'he end 'ofthe treatment period, the bottom of there'ceptac-le isopened, the receptacle "being "otherwise aclos'erl to "atmosphere,

and' the treated 'prddu'ctsare discharged'from" the receptacle downwardthrough a continuous *column of liquid, in the same manner as describedabove with're'ferenceto cannedproducts. That 1 eiifec'ts asubstantiarsaving "in time' and i equipment inhandling fruits andvegetables and other 'uncanned articles, *while also guarding Fagainstbruising 'of' or injury to "articles'of a character subject "to bruisingor "injury by striking "one againstthe othefland at the same time makingit possible "to handle such products or articles in greater depth thanisp'racticable by conventional batch handling practices.

It is"wel1*known'inindustrial processes/to treat articlesfboth metallicand non-metallic, in baths "or soliitionsior'various purposes. Forexample, metallic articles may be immersed pickling baths orinpxi'dizing baths, in suitable receptacles. 'Also"'non=rnetallicarticles maybe im- "mersed in bath-s for I cleaningpcoloring, coating orother "purposes. In many cases the articles to be treated are rathersmall and thei-present 1 practice is to place them in baskets "orcontainerslfor immersion and removal from the bath.

"Such articles are well suited 'for handling :in

"accordancewith the method ofmy'invention.

' They may be-"delivered directly into the'bath, in

a suitable receptacle, without the useof baskets or otherponta'iners. Attheend'o'f the treatment periodf the bottom of the receptacle "isopene'd,

the -receptacle "being "otherwise 'closed to atif they'are fragile'orofla'character 'to be injured by striking-one againstthe other.

In thelabove' description itrhas'beemassii-medv that the articles 'orproducts treated are heavier, or of greater specific gravity,=thanthetreating liquid, "and are discharged from the receptacle 'by fgravity downward through :the sustained 'column 'of' liquid, the valve-'25 remaining :closed 1 and the pump-23 not being operated. The methodof -my--invention may also be used to advantage 1 in the handling andtreatment of articles or :products which are lighter, or of lessspecific gravity,-than the treatingliq-uid. For -exarnple,ap--

.ples which have not been blanched asabove, peaches and I pears, afterpeeling and preparatory to further-processing thereof, *are immersed inwater-or brine, to prevent oxidation and browning, in which theytend tofloat. Tomatoes,

- which may be'advantageously heldin=water,; preparatory to canning,tend to float in the bath. Also, in'industrial' operations, theremaybe-articles formed'of wood or other "light-materials "which it isdesirable to treat in a liquidbath: for

fh'vi-the' bottom of the receptacle after treatment of the receptacle Ivarious purposes :and which tend to float in" the bath. 'In order todischarge downward through the sustained column of liquid articles orproducts of less specific gravity than" the treating liquids, whenthe-lower end of the receptacle is opened, the valve 425 is'op'ened andthe'pump 23 isaset into operation. The pump 23 withdraws liquid fromtank I9 and dischargesit into thetop of The water or other'liquid thusflows in a closed circuit and downward through the sustained column ofliquid extending from the interiorofreceptacle I into tank I9. That doesnot disturb the continuity of the column of liquid, due tothe fact thatthe water or other liquid'is returned to'the receptacle I at the samerate at'which it is withdrawn from'the tank I9. The liquid 'flowingdownward through the sustained liquid column creates a currentflowingdownward from the upper surface of the-liquid into tank I9. Thatdownwardly flowing current entrains the treated articles and carriesthem downward into tank l9, so that they are rapidly discharged from thereceptacle I downward through the sustained column of liquidin much thesame manner as the heavier articles or products, previously referred to,thoughnot by gravity alone. If desired, in'handling or treating articlesor products of reater specific gravity than the treating liquid, thevalve'25 may be opened and the pump 23 operated tocreate a down currentfor expediting the discharge of such articles, though ordinarily that isnot necessary. Within the broader aspects of my invention, a downcurrent through the sustained water column, to assist in discharging thetreated articles as above explained, maybe created in any suitablemanner.

It will be clear from the above, that the method of my invention, whileparticularly suitable in certain of its aspects for the handling orprocessing of canned products, is, in its broader aspects, wellfitted'for the handling or treatment of any suitable discrete articlesin" industrial operations, including 'both edible and inedible articles,as well as metallic andnon-metallic articles. As previously noted, themethod of my invention, inits' broader aspects, is not limited to thetreatmentor handling of food stuffs and may be used in connection 'withany discrete articles susceptible to treatment by that method.

'It will be understoodthat changes, bothas to the methodand'theapparatus, may-be resorted to without departing from the'fieldandscope of my invention, andI intend to include I'claim: :1. The method ofbatch processing canned products, which comprises delivering 1 thefilled and closed cans into a body of water within a retort,draining-thewaterfromthe retort and t'hereaftersteam processingthe cansin the retort,

cooling the cans by refilling the retort with water, and discharging thecans downward from the retort by gravity through a continuous column ofwater by opening the bottom of the retort to a connecting underlyingbody of water subject to atmospheric pressure while maintaining theretort :otherwise closed to the atmosphere.

.2. In a methodlof batch processing :discrete articles by treatingthe'articles in a liquid bath within a receptacle, the novelfsteps ofopening 9 the articles, to a connecting underlying body of liquidsubject to atmospheric pressure while maintaining the receptacleotherwise closed to the atmosphere, thereby providing a continuoussustained column of liquid extending from the interior of the receptacleto said underlying body of liquid, and discharging the treated articlesfrom said receptacle downward through said liquid column.

GEORGE M. FLYNN.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date Smith Jan. 2, 1900 Donnellan Aug. 15, 1922 Hansen Dec. 18,1923 Fooks Apr. 20, 1926 Thomas Dec. 23, 1941

1. THE METHOD OF BATCH PROCESSING CANNED PRODUCTS, WHICH COMPRISESDELIVERING THE FILLED AND CLOSED CANS INTO A BODY OF WATER WITHIN ARETORT, DRAINING THE WATER FROM THE RETORT AND THEREAFTER STEAMPROCESSING THE CANS IN THE RETORT, COOLING THE CANS BY REFILLING THERETORT WITH WATER, AND DISCHARGING THE CANS DOWNWARD FROM THE RETORT BYGRAVITY THROUGH A CONTINOUS COLUMN OF WATER BY OPENING THE BOTTOM OF THRETORT TO A CONNECTING UNDERLYING BODY OF WATER SUBJECT TO ATMOSPHERICPRESSURE WHILE MAINTAINING THE RETORT OTHERWISE CLOSED TO THEATMOSPHERE.